PCB Mounted Rotary switch for Bridged T attenuator.

[Gustav]

So use a small sub pcb for the 2x6 shorting Lorlin switch

Something like this attached image with connector like...

...this - http://www.toby.co.uk/content/catalogue/products.aspx?series=THD-xx-R-RA ?

I used random pin connections and the auto-router for this example, but putting a little more thought into it could probably improve it a lot.

If this would do the job, I can try do it single sided and share a self etch file...Seems like a fun challenge .

IF its possible to turn the pins upwards into the solder side of the board it connects to and successfully solder it (pins going in at solder side), it wouldn't even take up a lot of space - that would require an experiment, and may be a little "greedy" though (and might not make sense the way I explained it!?)

We rarely need more than 2x5 for stuff like this, right?

1,4 inches high.

Gustav

Hey Gustav, thats a great idea! Another option would be to have all the resistors loaded up on the sub board and then just have 3-4 pins coming out. Might make it more forgiving to mount and reduce soldering time (Less connections), however it would limit the use of the board considerablly....

Where did you get the Eagle part for the Lorlin 2x6?

I thought you were looking for "just the switch" as a single entity (which I would find useful myself). What you are suggesting has been done on a lot of projects - Check Jakob's 1176 for an example. http://www.gyraf.dk/gy_pd/1176/1176.pdf

Switch is in the "switch.lbr" library - part CK102X06. I think it was part of the default library, but I may have added it. Let me know if you can't find it.

Gustav

 

[iampoor1]

So use a small sub pcb for the 2x6 shorting Lorlin switch

Something like this attached image with connector like...

...this - http://www.toby.co.uk/content/catalogue/products.aspx?series=THD-xx-R-RA ?

I used random pin connections and the auto-router for this example, but putting a little more thought into it could probably improve it a lot.

If this would do the job, I can try do it single sided and share a self etch file...Seems like a fun challenge .

IF its possible to turn the pins upwards into the solder side of the board it connects to and successfully solder it (pins going in at solder side), it wouldn't even take up a lot of space - that would require an experiment, and may be a little "greedy" though (and might not make sense the way I explained it!?)

We rarely need more than 2x5 for stuff like this, right?

1,4 inches high.

Gustav

Hey Gustav, thats a great idea! Another option would be to have all the resistors loaded up on the sub board and then just have 3-4 pins coming out. Might make it more forgiving to mount and reduce soldering time (Less connections), however it would limit the use of the board considerablly....

Where did you get the Eagle part for the Lorlin 2x6?

I thought you were looking for "just the switch" as a single entity (which I would find useful myself). What you are suggesting has been done on a lot of projects - Check Jakob's 1176 for an example. http://www.gyraf.dk/gy_pd/1176/1176.pdf

Switch is in the "switch.lbr" library - part CK102X06. I think it was part of the default library, but I may have added it. Let me know if you can't find it.

Gustav

Well initially I was, but then other ideas got suggested, we rolled with them, and its already been done.  ;D

I would still be very interested in a PCB for just the switch, but for different applications.

 

[Gustav]

other ideas got suggested, we rolled with them

;D

I fell in love with the idea of shaping the board, so no way of adding resistors until I sober up again.

Gustav

 

[Harpo]

So use a small sub pcb for the 2x6 shorting Lorlin switch, the 2x5+2=12 resistors and a 3-pin molex type connector.

something like this maybe ?  :-\ (resistors upright on traceside or fit some MELFs instead).

 

[iampoor1]

other ideas got suggested, we rolled with them

;D

I fell in love with the idea of shaping the board, so no way of adding resistors until I sober up again.

Gustav

For some reason this reminds me of a demented squid!  ;D

 

[ding]

I know this is an old thread but I need to understand something about Harpo's excel spreadsheet. It seems like the Bridged-T and Balanced-Bridged-T numbers look right to me but when I go to the low cost stepped bridged-t page and the low cost balanced bridged-t page the E-96 parts value numbers dont match up. Am I missing something here that I don't quite understand?

 

[ding]

And the regular Bridged-T sheet.

 

[abbey road d enfer]

I know this is an old thread but I need to understand something about Harpo's excel spreadsheet. It seems like the Bridged-T and Balanced-Bridged-T numbers look right to me but when I go to the low cost stepped bridged-t page and the low cost balanced bridged-t page the E-96 parts value numbers dont match up. Am I missing something here that I don't quite understand?

It seems the Bridged-T sheet is correct for zero source-impedance and 600r load.
The 1st column of the "low-cost" sheet is more or less correct, albeit somewhat different, but the differences are minor.
The 2nd column should into account the output impedance of the 1st attenuator and leave me perplexed as to what load impedance it sees. Anyway the second attenuator makes no sense. No combination is correct.

 

[moamps]

It looks that it works for me .
(10dB + 2dB)

 

[moamps]

26dB

 

[abbey road d enfer]

It looks that it works for me .
(10dB + 2dB)

I hadn't noticed the resistors were in series, so the value in the table is the complement.

 

[ding]

It looks that it works for me .
(10dB + 2dB)

I hadn't noticed the resistors were in series, so the value in the table is the complement.

That makes 2 of us. !!!!!

 

[Bo Deadly]

Beware that the particular switch you cite does not have contacts for all positions. The end positions are actually open at one or the other pole. I bought some of these switches once only to find out they have screwy contacts. IIRC they also don't have a wide rotation angle. Otherwise, they're nice switches. They have a nice feel to them.

I bought about 10 different kinds of rotary switches one time to see what they were like. They were all pretty bad in one way or another. They grayhill switches are probably considered the best but they're kinda hard to switch IMO.

 

[Bo Deadly]

Beware that the particular switch you cite does not have contacts for all positions. The end positions are actually open at one or the other pole.

Actually it just occurred to me that this switch, with it's open end contacts, is ideal for making a bridged t attenuator. It's probably designed for just that purpose. Mmm.